Abrasive materials are used in various industries to remove bulk material or to affect surface characteristics of products, such as shine, texture, and uniformity. For example, manufacturers of metal components use abrasives to refine and polish surfaces to a uniformly smooth surface. Similarly, optics manufacturers use abrasive materials to produce defect-free surfaces that prevent unwanted light diffraction and scattering. In addition, semiconductor manufacturers may polish substrate materials to produce low defect surfaces for formation of circuit components.
Manufacturers typically desire abrasive materials that have a high stock removal rate for certain applications. However, there is often a trade-off between removal rate and quality of polished surfaces. Finer grain abrasive materials typically produce smoother surfaces but can have lower material removal rates. Lower material removal rates lead to slower production and increased cost. On the other hand, larger grain abrasive materials have higher material removal rates but can contribute to scratches, pits and other deformations in polished surfaces.
Cerium (IV) oxide, or ceria, is a ceramic particulate used in the polishing of SiO2-based compositions. Generally, ceria removes SiO2 during polishing by mechanical means. Further, its chemical activity with respect to the SiO2 improves the removal rate when compared with other materials. In order to use ceria-based particles in electronic applications, such as semiconductor chemical-mechanical polishing (CMP), photomask polishing, or hard disk polishing, the particles should be sufficiently abrasive to polish at a high rate without causing scratches, pits or other deformations in the polished surface and further, should be free of contaminants. Such defects and contaminants increase in significance as device manufacturing technologies continue to reduce the feature size.
As such, an improved abrasive particulate and abrasive slurries formed thereof would be desirable.